Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthesis of brookite TiO2 nanoparticlesby thermolysis of TiCl4 in strongly acidic aqueous media

Nanometric particles of titania, brookite and rutile polymorphs were synthesised by thermolysis of TiCl4 in concentrated HCl solutions. The Cl∶Ti molar ratio seems to be the key factor in determining the crystalline phases and their relative proportions as well as the particle size and a large proportion of brookite can be obtained under specific conditions. The complex Ti(OH)2(Cl)2(OH2)2 seems to be the precursor of the brookite phase. The presence of chloride ions is also necessary to stabilise brookite in suspension. Depending on the acidity and the ageing conditions, different morphologies of brookite nanoparticles are obtained, namely spheroidal particles or platelets. Stable sols of pure brookite are obtained by peptization of the solid phase.
Hydrothermal Reaction-Sintering of Monoclinic HfO2

Sintered monoclinic HfO2 bodies were fabricated below the transformation temperature from Hf metal and water by hydrothermal reaction-sintering. Sintering was observed above 900°C under 100 MPa for 3 h. Generally, both the bulk density and the crystallite size of the sintered bodies increased with increasing temperature. Bodies with the maximum relative density (0.98) were obtained by treatment above 1000°C.
Lissamine FF Fluorescent Dye

The use of Rhodamine WT fluorescent dye in the presence of nitrite was recently linked with the formation of diethylnitrosamine (DENA), a compound with mutagenic and carcinogenic properties. Lissamine FF fluorescent dye was selected as a substitute for Rhodamine WT dye to avoid potential problems upstream of water intakes. In a series of comparative tests with Rhodamine WT dye, Lissamine FF dye was found to have a higher minimum detectability limit, to be less temperature dependent, to be highly sensitive to chlorine content, to be less soluble, and more expensive than Rhodamine WT.
Macroporous silica and titania obtained using poly[styrene-co-(2-hydroxyethyl methacrylate)] as template

Ordered macroporous silica and titania have been prepared using poly[styrene-co-(2-hydroxyethyl methacrylate)] (PS-HEMA) latex arrays as templates. Polystyrene (PS) particles have also been used to template macroporous titania. Arrays of spherical latex particles, with average diameters of 260 nm (PS-HEMA) and 390 nm (PS), have been obtained by either evaporation of the solvent at room temperature or by deposition on filtration membranes. In both cases, 3D extended regions with cubic close packing of microspheres are observed, but in the samples obtained after evaporation of the solvent the self-assembled particles show a higher degree of order. The oxides were synthesized by hydrolysis of sodium silicate or titanium isopropoxide (diluted in n-propanol or hexane) which were infused into the cavities of the latex arrays. Two different methods have been used to fill the cavities with the precursor: filtration with suction and capillary forces. When solidification of the ceramic matrix took place, the template was eliminated by heating at 500 °C. As replica of the latex assemblies, periodic porous silica and titania were obtained. Sheets of amorphous silica, as thin as 4–7 nm, form the wall of the interconnected pores whose diameters range from 200 to 220 nm. In macroporous titania obtained from titanium isopropoxide diluted in n-propanol and imprinted on PS-HEMA particles, the pore diameters range from 160–180 nm. The porous network is shaped by walls that are 8–12 nm thick and are formed from anatase nanocrystals with a major dimension of 8–20 nm. Pore diameters, crystallite sizes and thicknesses are similar when hexane is used as the solvent of the inorganic precursor. However, in macroporous titania imprinted on PS particles, nanocrystals with a major dimension of 6–10 nm form the pore wall with a thickness of 6 to 8 nm. Interactions between the titania precursor and the latex particles seem to affect the microstructural parameters. The porous skeleton of titania is preserved after treatment at 600 °C for 16 hours but the pore wall thickness slightly increases with crystallite growth and in some particles disordered areas appear.
Interaction between Cu(II) Compounds and Amyloid β‐peptide (1–40) in Solution

Capillary electrophoresis (CE) and ESR spectral measurements have revealed that amyloid beta‐peptide (1–40) interacts with the copper(II)‐(dpgt) complex specifically in solution, leading to an aggregation of the Cu(II)‐complex, but the analogous copper complex with (dpa‐GMe) did not aggregate under the same experimental conditions, where (dpgt) represents N,N‐bis(2‐pyridylmethyl)glycylglycylglycine. These facts seem to be very important to elucidate the origin of the abnormal storage of the metal ions such as copper or iron ions in the senile plaques of Alzheimer's disease patients brain tissue.
High Efficiency SOFC Power Cycles With Indirect Natural Gas Reforming and CO2 Capture

Driven by the search for the highest theoretical efficiency, several studies have investigated in the last years the adoption of fuel cells in the field of power production from natural gas with CO2 capture. Most of the proposed power cycles rely on high temperature fuel cells, namely Solid Oxide Fuel Cells (SOFC) and Molten Carbonate Fuel Cells (MCFC), based on the concept of hybrid fuel cell plus gas turbine cycles. Accordingly, high temperature fuel cells are integrated with a simple or modified Brayton cycle. As far as SOFC are concerned, two main plant solutions can be identified depending on the integration with the natural gas reforming/shift section: (i) systems where natural gas is — partially or totally — internally reformed in the fuel cell and (ii) systems where natural gas is reformed before the fuel cell and the cell is fed with a high hydrogen syngas. In both cases, CO2 can be separated downstream the fuel cell via a range of available technologies, e.g. chemical or physical separation processes, oxy-combustion and cryogenic methods.Following a literature review on very promising plant configurations, this work investigates the advantages and limits of adopting an external natural gas conversion section with respect to the plant efficiency. As a reference plant we considered a power cycle proposed by Adams and Barton [8], whose performance is the highest found in literature for SOFC-based power cycles, with 82% LHV electrical efficiency. It is based on a pre-reforming concept where fuel is reformed ahead the SOFC which thus works with a high hydrogen content fuel. This plant was firstly reproduced considering all the ideal assumptions proposed by the original authors. As second step, the simulations were focused on revising the power cycle, implementing a complete set of assumptions about component losses and more conservative operating conditions about fuel cell voltage, heat exchangers minimum temperature differences, maximum steam temperature, turbomachinery efficiency, component pressure losses and other adjustments.Considering the consequent modifications with respect to the original layout, the net electric efficiency changes to around 66% LHV with nearly complete (95%+) CO2 capture, a still remarkable but less attractive value, while requiring a very complex and demanding heat exchangers network. Detailed results are presented in terms of energy and material balances of the proposed cycles. All the simulations have been carried out with the proprietary code GS, developed by the GECOS group at Politecnico di Milano.Copyright © 2014 by ASME
Distribution, Fate, and Behavior of Nonylphenol Ethoxylates and Degradation Products in the Dispersion Plume of a Major Municipal Wastewater Effluent

The aim of this study was to estimate the distribution, fate, and behavior of p-nonylphenols (p-NPs: p-n-nonylphenol and its isomers), nonylphenol ethoxylates (NP1–17EOs), and nonylphenol carboxylic acids (NP1–2ECs) in the municipal wastewater effluent (MWWE) of the City of Montreal, Canada, and in the receiving waters of the St. Lawrence River. The MWWE was sampled at the Montreal wastewater treatment plant, while surface water was sampled at sites located upstream and downstream of the effluent outfall. Twenty-four hour composite samples were obtained at the treatment plant on three nonconsecutive days during the summer of 2002. Water samples were filtered, then particulate and dissolved phases were extracted using Soxhlet and solid-phase extraction techniques, respectively, prior to LC/MS/MS analysis for the compounds of concern. The effluent contained essentially dissolved (75.4%, 375 kg/day) and particulate (23.7%, 118 kg/day) NP1–17EOs. By contrast, the surface water downstream of the outfall contained p-NPs at an average of 9.8% and dissolved NP1–2ECs (1.3%), as well as dissolved NP1–17EOs (86.7%) and a small fraction of particulate NP1–17EOs (2.1%). All NPnEOs and their degradation products were present in higher amounts in the dissolved phase (particulate/dissolved ratio < 1) than in the particulate phase in both the wastewater and surface water. In the surface waters downstream of the effluent outfall, an average of 89% of the particulate NP1–17EOs was rapidly released (within 1.5 h) into the dissolved phase during the physical exchange, and there were variances in changes in the phase distribution among the compounds being studied. Following this relatively fast phase transfer in the receiving waters, 30% of total NP1–17EOs were lost, 25% of p-NPs and NP1–2ECs were formed by the degradation of a fraction (6%) of NP1–17EOs, and 24% of NP1–17EOs loss remains unexplained.
Activation mechanism of annealed Mg-doped GaN in air

In this study, the activation mechanism of annealed Mg-doped GaN in air and the influence of ambient on activation of Mg-doped GaN were investigated. According to the experimental results, we found that the dissociation of MgGa–H, and the formation of hydrogenated gallium vacancies (VGaH2) and gallium vacancies occupied by interstitial Mg during the air-activation process, led to an increase in the hole concentration. In addition, from the observed photoluminescence results and the secondary ion mass spectroscopy measurements, it is suggested that the formation of VGaH2 will result in an enhancement of hydrogen desorption from the MgGa–H complexes.
Effect of the premelting temperature and sample thickness on the polymorphic behavior of syndiotactic polystyrene/clay nanocomposites

X-ray diffraction methods and differential scanning calorimetry thermal analysis have been used to investigate the structural changes of syndiotactic polystyrene (sPS)/clay nanocomposites. sPS/clay nanocomposites have been prepared by the mixing of sPS polymer solutions with organically modified montmorillonite. X-ray diffraction data and differential scanning calorimetry results indicate that the dominating crystal forms and their relative fractions in sPS and sPS/clay nanocomposites are different for various premelting temperatures (Tmax's). Higher Tmax's favor the formation of the thermodynamically more stable β-crystalline form, and its relative fraction has been obtained from the X-ray diffraction data in the range of 11.5–13°. The intensity of the X-ray diffraction data in the range of 11.5–13° decreases as the thickness of sPS/clay nanocomposites decreases from 150 to 20 μm. At the same time, the intensity of the X-ray data in the range of 6–7° becomes sharper as the thickness of sPS/clay nanocomposites decreases. The calculation ratio based on the peak intensities at 6.2 and 6.8° for sPS/clay nanocomposites of equal thickness and crystallinity in the pure β and α forms has also been determined in this study. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1730–1738, 2003
Immobilization of Chymotrypsin on Silica Beads Based on High Affinity and Specificity Aptamer and Its Applications

Aptamers with high affinity and specificity to targets, bring new approaches to immobilizing proteins or enzymes. In this work, a group of single-stranded DNA aptamers specific for chymotrypsin were obtained by SELEX method in vitro. After investigation and characterization of all aptamers, AptC.1 (abbreviation for the aptamer with the highest affinity for chymotrypsin) was selected and grafted onto silica matrix with the help of glutaraldehyde as linker, and used subsequently to immobilize chymotrypsin. Specifically, it is shown in experiment that, 12.65 µg of chymotrypsin could be immobilized on 10 mg of AptC.1-Silica in 10 mM pH 8.0 borate solutions, and the activity of immobilized enzyme was not inhibited. Bovine serum albumin, myoglobin and cytochrome c were introduced to investigate the enzymatic performance of prepared immobilized chymotrypsin reactor. All these results demonstrated that aptamer could serve as a potential medium for the immobilization of proteins or enzymes.
A combined retarding field analyser and E×B probe for measurement of ion and electron energy distribution in tokamak edge plasmas

A new probe has been designed to measure the electron and ion energy distributions in a tokamak edge plasma; it may be operated in both the retarding field analyser and E*B modes. In this type of probe aperture design is important and must include detailed consideration of Debye length, selective transmission, heat flux and space charge effects. Results obtained in the retarding analyser ion mode show that the ion parallel velocity distribution function as measured by the probe is a displaced Maxwellian in accordance with theoretical prediction. The electron parallel velocity distribution on the other hand is seen to be cut off by the wall sheath. Ion temperatures obtained under similar conditions in the E*B mode are in agreement with values obtained by fitting theoretical distributions to retarding field ion mode characteristics. The results which are presented were obtained in the edge region of discharges with line average densities of 1019 m-3. In this particular case approximately equal ion and electron temperatures of order 15 eV were measured. There is experimental evidence that at the current levels used space charge effects are negligible.
A Systematic Optimization Scheme for Configurational Bias Monte Carlo

Abstract We present a simple method that allows us to optimize the efficiency of Monte Carlo schemes that employ trial moves composed of a sequence of elementary steps. One such scheme, namely the Configurational Bias Monte Carlo (CBMC) method, has resulted in great advances in the simulation of phase behavior of chain molecules. Until now the construction of efficient CBMC trial moves was more an art than a science. In this paper we show that there exist simple relations that allow us to design the most efficient CBMC trial moves, for a given temperature and density. The best strategy will vary between random regrowth (in the case of an almost ideal chain) and reptation (in the limit of a dense melt), both of which are special cases of a CBMC trial move. We also show how the same approach can be used to optimize the calculation of the chemical potential of a chain molecule, using the Rosenbluth particle insertion scheme.
Development of Melting System for Measurement of Trace Elements and Ions in Ice Core

We present a titanium (Ti) melting head divided into three zones as an improved melting system for decontaminating ice-core samples. This system was subjected to performance tests using short ice-core samples (4 × 4 cm2, ~5 cm long). The procedural blanks (PBs) and detection limits of ionic species, with the exception of NO 3 − , were comparable with published values, but for elements the experimental procedures should be refined to obtain valid Zn concentrations due to the PB of ~90.0 ± 16.2 ng/L. The improved melting system efficiently decontaminated the samples, as verified by the concentration profiles of elements and ions in the melted samples from the three melting-head zones. The recovery of trace elements in ice-core samples was ~70–120% at ~100 ng/L in artificial ice cores. Because of the memory effects between ice-core samples melted in series, the melting system should be rinsed at least 5–6 times (in a total volume of ~2.5 mL deionized water) after each melting procedure. Finally, as an application of this technique, trace elements were measured in ice-core samples recovered from the East Rongbuk Glacier, Mount Everest, (28°03′N, 86°96′E, 6518 m a.s.l.), and the concentrations of trace elements following mechanical chiseling and the melting method were compared.
Polystyrene-Grafted Magnetite Nanoparticles Prepared through Surface-Initiated Nitroxyl-Mediated Radical Polymerization

Surface-modified magnetite (Fe3O4) nanoparticles (d = 10 nm) was prepared by direct polymerization of styrene on their surface. With use of nitroxyl-mediated initiator for radical polymerization with the phosphonic acid group, magnetite particles with a controlled polystyrene graft layer on the surface were successfully prepared. The surface-modified magnetite was dispersed in good solvents for polystyrene such as chloroform, toluene, ethyl acetate, and benzene.
Simultaneous determination of urinary metabolites of toluene, xylene, styrene and ethyl benzene by solid-phase extraction technique and high-performance liquid chromatographic/photo diode array detection

Abstract To determine the level of urinary hippuric acid, methylhippuric acid, mandelic acid, and phenylglyoxylic acid, a method by solid-phase extraction (SPE) pretreatment and reversed-phase high performance liquid chromatography with photo diode array detection has been developed in this study. Six milliliter of methanol is the only solvent used in the SPE procedures. After extraction, the urine sample is injected onto a 5 (μn RP18-LiChrospher 100 column (150 mm × 4 mm I.D.). The mobile phase is a mixture of acetonitrile (15 parts) and phosphate buffer (85 parts) containing tetrabutyl ammonium hydrogen sulfate (8.5 mM). The entire procedure is performed in 40 min. The method is simple, rapid and highly specific, and applicable in field study of toluene, xylene. styrene and ethyl benzene exposure.
Sensitive Biosensors Based on (Dendrimer Encapsulated Pt Nanoparticles)/Enzyme Multilayers

A sensitive enzymed-based biosensor for glucose has been obtained by introducing dendrimer encapsulated Pt nanoparticles via a layer-by-layer assembling method. The free amine groups located on each poly(amidoamine) dendrimer molecule were exploited to covalently attach enzyme to the dendrimer chains using carbodiimide coupling. The resultant enzyme electrodes are shown to have excellent sensitivity (as high as 30.33 μA mM−1 cm−2) and a limit of detection (about 0.1 μmol L−1), depending on metal nanoparticles within dendrimers and the biocompatibility of dendrimers, the linear response range to glucose (from 5 μM to 1.0 mM), a fast response time (within 5 s), and good reproducibility (<8% relative standard deviation between electrodes at low substrate concentration). The sensitivities, and stabilities determined experimentally have demonstrated the potential of dendrimer encapsulated Pt nanoparticles as a novel candidate for enzymatic glucose biosensors.
Valence quantum Monte Carlo with ab initio effective core potentials

Effective‐core potentials (ECP’s) obtained from ab initio methods are implemented in molecular quantum Monte Carlo (QMC). The theory is presented, and applied to the calculation of electron affinities (EA) of Li and Na, the ionization potential (IP) of Mg, the binding energies (De) of NaH and Na2, and the potential energy curve of Na2. In all cases ECP–QMC results are found to be as accurate as previous all‐electron results. In particular, the calculated quantities (vs experimental values) are (in eV): EA(Li)=0.611±0.020 (0.620), EA(Na)=0.555±0.021 (0.546), IP(Mg)=7.637±0.026 (7.646), De (NaH) =1.954±0.073 (1.971), and De (Na2)=0.746±0.020 (0.747). In addition, the statistical precision obtained surpasses that which can be readily achieved in all‐electron QMC calculations on these systems.
On the presence and distribution of the Gulf sand gecko, Pseudoceramodactylus khobarensis Haas, 1957 (Reptilia: Squamata: Gekkonidae) in Qatar

The Gulf sand gecko (Pseudoceramodactylus khobarensis Haas, 1957) is a nocturnal gecko endemic to the Arabian Gulf countries. In this study we report the presence of this species in Qatar for the first time. Our findings bridge one of the current geographic gaps in the known distribution range of this species. In Qatar, the species has been found on the mainland and on two islands occupying coastal salty habitats with shrubs. The islands are the smallest where this species is known to occur. We believe that this gecko species is more widely distributed in Qatar than we report here and that an extensive inventory is required to map the full range of the species in Qatar and also in other countries of the Arabian Gulf.
Incorporation of tris(2,2′-bipyridine)ruthenium(II) in a synthetic swelling mica with poly(vinylpyrrolidone)

Tris(2,2‘-bipyridine)ruthenium(II) ([Ru(bpy)3]2+)−fluortetrasilicic mica−poly(vinylpyrrolidone) intercalation compounds were prepared by the intercalation of poly(vinylpyrrolidone) into the presynthesized [Ru(bpy)3]2+−fluortetrasilicic mica intercalation compounds. The formation of the intercalation compounds was confirmed by the expansion of the interlayer space as well as the spectroscopic observations. Intercalation compounds with variable chemical compositions have been prepared, and the effect of the distribution of the intercalated [Ru(bpy)3]2+ on the luminescence has been discussed. The luminescence probe can be utilized for the study of clay−polymer interactions.
Novel Synthesis of Heterocyclic Ketene N,N-, N,O-, and N,S-Acetals Using Cyanoketene Dithioacetals

Abstract A novel synthesis of (2,3-dihydrobenzoimidazole-2-ylidenyl)cyano-acetanilide, (2,3-dihydrobenzoxazole-2-ylidenyl)cyanoacetanilide and (2,3-dihydro-benzothiazole-2-ylidenyl)cyanoacetanilide derivatives 5a–l via reaction of ketene dithioacetals 2a–d with o-phenylenediamine, o-aminophenol, and o-aminothiophenol 3a–c is reported and the synthetic potential of the method is demonstrated.
Detailed H(n = 2) density measurements in a magnetized hydrogen plasma jet

We present detailed spatial density measurements of H(n = 2), i.e. the first excited state of atomic hydrogen, in a hydrogen plasma expansion that is weakly magnetized. At a specific distance from the source of the expansion a sharp transition from a red light emitting plasma (dominated by Hα emission) to a blue light emitting plasma (dominated by Hβ and Hγ emission) occurs. Molecular processes such as dissociative recombination and processes with negative ions are suspected to be key in the understanding of the distinct emissions observed in the two different plasma regions. The relevance of the presented work is to underline these molecular processes in atomic regimes of hydrogen-containing plasmas. The first excited state density, n = 2, is determined with tunable diode laser absorption spectroscopy on the Balmer-alpha transition to investigate how important molecular processes such as dissociative recombination are in the plasma. The density of n = 2 is 1 × 1017 m−3 close to the plasma source and decreases gradually along the plasma column to 1014 m−3 at 20 cm from the plasma source exit. The presented results show that the theoretical possibility to generate a stable hydrogen laser in the visible light, i.e. population inversion of n = 3 with respect to n = 2, is not obtained due to the population of n = 2 by dissociative recombination of ions. The presence of molecular processes in the plasma is further evidenced with the use of a collisional radiative model.